The company requires smokers to pay an additional $500 in insurance premiums, the Evansville Courier-Press reported. Debby Castrale said the employees were spotted in outdoor smoking areas after signing insurance enrollment forms.

"Falsification of company documents is one of the most serious offenses our employees can commit," she said. "We treat it very seriously."

The suspensions follow a dismissal of a suit between the company and a union over the smokers' insurance surcharge. Details of the dismissal have been sealed.

Castrale said the company plans to investigate other production workers and administrative staff.